Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/065—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of foam
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2266/00—Composition of foam
  • B32B2266/02—Organic
  • B32B2266/0214—Materials belonging to B32B27/00
  • B32B2266/025—Polyolefin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/30—Properties of the layers or laminate having particular thermal properties
  • B32B2307/31—Heat sealable
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2439/00—Containers; Receptacles
  • B32B2439/70—Food packaging
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
  • Y10T428/1352—Polymer or resin containing [i.e., natural or synthetic]
  • Y10T428/1376—Foam or porous material containing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24479—Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness
  • Y10T428/24496—Foamed or cellular component
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24479—Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness
  • Y10T428/24496—Foamed or cellular component
  • Y10T428/24504—Component comprises a polymer [e.g., rubber, etc.]

Definitions

• the invention is in the field of the packaging industry and relates to a packaging material which comprises a foamed polyolefin layer as the outer layer, which has further layers on one of its surfaces, and packages made therefrom.
• Packaging materials having a foam layer of, for example, polypropylene in the form of quasi-continuous, rolled up webs are used to make thermoformed, self-supporting packages, such as troughs for food packaging.
• packaging materials on so-called "FFS machines” form-fill-seal machines
• FFS machines form-fill-seal machines
• the web-shaped packaging material fed into a mold device there formed into a web of troughs, filled into the wells the packaged and with a preferably transparent film is sealed by sealing. Subsequently, the closed wells are separated from each other.
• the layer of foamed polyolefin is provided with further layers at least on one surface side. Depending on the composition and thickness of these layers, these may increase the stiffness of the packaging material and / or serve as protection of the foam surface and / or as a gas and / or aroma barrier and / or as a surface layer for sealing a filled packaging tray with a preferably transparent lidding film.
• Packing materials with a layer of foamed polypropylene for the production of packaging troughs by heat deformation for example, in EP-A-0 570 222 described. These materials include a foam layer and a multilayer composite film which may optionally contain a barrier layer which makes the packaging material gas and aroma resistant. This multi-layer packaging material does not always have the desired properties for self-supporting packaging.
• EP-B-1 117 526 It is disclosed to complement the foam layer with a compact layer of a polyolefin of the foam layer while maintaining a certain thickness ratio of these two layers to each other to improve the self-bearing capacity of packaging made from this packaging material without increasing the thickness of the packaging material.
• the total thickness of the layers A) and B) is in the range of 0.6 to 1.4 mm and the thickness of the layer B) in the range of 1/6 to 1/3 of the thickness of the layer A).
• the foam layer A) consists of at least one foamed polyolefin.
• Foamed propylene homo- and / or copolymers are particularly suitable for the production of packaging, such as packaging trays for the packaging of foodstuffs, since these materials have self-supporting properties even with a small thickness and a low density. It is also possible to use blends of polyolefins to make the foam layer. In particular, a mixture of polypropylene with a Langkettenverzweigung and thus high melt strength and a propylene ethylene copolymer, such as. B. a heterophasic propylene-ethylene block copolymers.
• the foaming of the polyolefin of layer A) can be effected by adding solid, liquid and / or gaseous foaming agents which are added to the polyolefin in conventional amounts, preferably in an amount of from 0.5 to 3% by weight. It is based on the revelation in EP-A-0 570 222 Reference, which is hereby incorporated by reference and is part of the present disclosure.
• the foam layer A) contains 0.5 to 25 wt.%, Preferably 2.1 to 20 wt.%, Particularly preferably more than 2.5 to 15 wt.%, Based on the total weight of the foam layer A), at least one nucleating agent.
• the nucleating agent is preferably finely divided with an average particle size in the range of 4 to 20 microns.
• Suitable nucleating agents are all known solid nucleating agents, preferably synthetic or natural inorganic compounds. Particular preference is given to using at least one nucleating agent selected from the group comprising talc, titanium dioxide, silicon dioxide, calcium carbonate, magnesium silicate, aluminum silicate, calcium phosphate and montmorillonite. Very particular preference is given to using talc.
• the nucleating agent is added to the polymer from which the foam layer is to be manufactured, preferably in the form of a masterbatch containing 30 to 60% by weight of nucleating agent in the polymer, and largely homogeneously distributed therein before foaming.
• the resulting foam layer A) is characterized by a high number of cells with relatively small size deviations.
• the cell number is equal to or greater than 250 cells / mm 3 , more preferably equal to or greater than 300 cells / mm 3 , to 600 cells / mm 3 whose size variations of the cells are in the range of ⁇ 15%, preferably ⁇ 10%.
• the density of the foam layer A) is preferably in the range of 0.35 to 0.55 g / cm 3 .
• the density and the number of cells can also by the process parameters such. As the extrusion temperature or other process parameters during the preferred production of the foam layer by extrusion and expansion can be varied.
• the layer B) of compact polyolefin is based essentially on at least one polyolefin of the foamed base layer A). If this base layer consists of foamed polypropylene or a foamed mixture of polypropylene and propylene-ethylene copolymer, the compact polyolefin layer B) is preferably based on polypropylene or a propylene-ethylene copolymer. Particularly preferred is a heterophasic propylene-ethylene block copolymer.
• the melt index (MFI) of the polyolefins used to make layer B) is preferably in the range of 1.8 to 5.5 g / 10 min. measured as indicated above.
• the thickness of the layer B) is 1/6 to 1/2, more preferably 1/6 to 1/3 of the thickness of the layer A).
• the layer C) is preferably present if the layers D) to G) are prefabricated by coextrusion, preferably by blown film coextrusion, and to be joined to the remaining layers.
• the layer C) is based on a polyolefin which is preferably made from a monomer which is also the main monomer of the polyolefins constituting the foam layer A). Therefore, if the layer A) consists of a foamed polypropylene and optionally a propylene-ethylene copolymer, the layer C) may consist of polypropylene, optionally having grafted maleic anhydride units. Copolymers of ethylene / vinyl acetate can also be used as further component.
• the thickness of the layer C) is preferably 5 to 25 microns, more preferably 8 to 15 microns.
• the multilayer films according to the invention have a low gas permeability, ie. H. have low oxygen and moisture permeability and a flavor protection, they have a barrier layer E).
• This barrier layer is preferably composed of an ethylene / vinyl alcohol copolymer having a proportion of ethylene of 32 to 45 mol%, preferably 35 to 42 mol%.
• the barrier layer E) can be connected with the bonding layer C) or with the sealing layer G) on its respective surface with the aid of an adhesion promoter layer D) or F).
• the material used for this purpose is preferably a propylene copolymer or a polyethylene having grafted maleic anhydride units.
• the surface layer G) which forms the second outer layer of the multilayer film according to the invention is preferably sealable and / or peelable. Therefore, to produce this layer, preferably a low density polyethylene (LDPE) having a melt flow rate (MFI) in the range of 0.5 to 8.0 g / 10 min, preferably in the range of 1 to 5 g / 10 min (2.16 kg, 190 ° C measured according to ASTM D1238) or an ionomer, such as.
• LDPE low density polyethylene
• MFI melt flow rate
• Example a copolymer of an ⁇ -olefin and an ethylenically unsaturated carboxylic acid, wherein the carboxyl groups in an amount of 20 to 100 mol% as a metal salt, preferably as Na salt, or an ethylene-vinyl acetate copolymer having a vinyl acetate content of 3 to 10 % By weight, preferably 4 to 6% by weight, used to make the sealable layer.
• a metal salt preferably as Na salt
• an ethylene-vinyl acetate copolymer having a vinyl acetate content of 3 to 10 % By weight, preferably 4 to 6% by weight, used to make the sealable layer.
• the sealing layer is also peelable.
• a mixture of LDPE and a polybutylene (PB) is preferably used as the layer material.
• the mixture preferably contains 15 to 30% by weight, preferably 20 to 28% by weight, of polybutylene.
• the polybutylene has a melt index (MFI) in the range of 0.3 to 2.0 g / 10 min (190 ° C and 2.16 kg according to ASTM 1238).
• the thickness of the surface layer is in the range of 10 to 50 ⁇ m, preferably 15 to 30 ⁇ m.
• the multilayer film of the present invention also comprises a barrier layer
• a polyolefin preferably a polyethylene having grafted maleic anhydride units can be used.
• the thickness of the respective adhesion promoter layer is in the range of 2 to 8 microns, preferably in the range of 3 to 6 microns.
• the surface layer G) may contain conventional and known antibiotics, lubricants and anti-blocking agents, such as.
• antibiotics such as.
• lubricants such as.
• anti-blocking agents such as.
• erucic acid amide polyalkylsiloxanes, such as. As polydimethylsiloxane and / or silica.
• All or only individual layers of the multilayer films according to the invention may contain stabilizers and further additives of known type.
• the layer B) 0.5 to 2 wt.% Of a white pigment, such as. As kaolin, calcium carbonate, talc, titanium dioxide or mixtures thereof.
• a white pigment such as. As kaolin, calcium carbonate, talc, titanium dioxide or mixtures thereof.
• Such inorganic pigments become the polymer from which layer B) is made is added, preferably in the form of masterbatch containing 30 to 70 wt.% of pigments.
• the multilayer films of the invention may preferably be prepared by conventional film blown coextrusion processes or by coextrusion flat film processes as far as the sequence of layers C) to G) is concerned, and preferably by an extrusion lamination step with the polyolefin foam layer A).
• the foam layer A) and the multi-layer film, consisting of the layers C) to G), so combined that between them, the layer B) is extruded.
• a sufficiently large pressure is applied to the thus-prepared laminate so that the layers A) to G) are sufficiently bonded to each other.
• the multilayer films according to the invention only by coextrusion, wherein the foam layer A) coextrudes simultaneously with the other layers, if necessary omitting the layer C), and the layer A) is foamed simultaneously.
• the multilayer films of the invention have excellent thermoformability on so-called FFS machines (forming, filling and sealing machines) and can be processed on these machines into packaging containers, preferably into deep-drawn packaging trays, then filled and sealed. It was surprising that the multilayer films according to the invention can be processed excellently on the FFS machines with an increased production speed and compared to a packaging material without modification according to the invention by up to 10% shorter cycle times and thus up to 10% higher output of packaging trays without affecting the Allow uniformity of the wall thicknesses.
• the multilayer films according to the invention also show, compared with the known, unmodified, comparable packaging materials, an unexpected improvement in the mechanical properties, in particular the stiffness measured by the modulus of elasticity in the machine direction and the tensile stress. This marked improvement is evident without the need to increase the thickness of the multilayer films known in the art.
• packages produced from the multilayer film according to the invention show a significantly more even surface structure with virtually no foam outlines, which also improves their handling.
• Another object of the present invention is therefore also the use of the multilayer films according to the invention as packaging material, preferably on form, fill and seal machines (FFS machines), for the packaging of food, in particular for the packaging of perishable foods, such as meat, ham or cold cuts. Since the packaging on these machines is often batched to package different goods, the packaging material must also have a relatively wide, so-called thermoforming window in which it can be thermoformed. This is the case with the packaging material according to the invention, since it has an excellent thermoformability, in particular a thermoformability.
• FFS machines form, fill and seal machines
• thermoformed packaging articles such as packaging trays, preferably thermoforming packaging trays, which were prepared from the multilayer films of the invention can be sealed after their filling with known lidding films.
• Suitable cover films are multilayer films, preferably of polyethylene terephthalate / SiO x / adhesive layer / low density polyethylene or of polyethylene terephthalate / adhesive layer / polyethylene / adhesive layer / ethylene-vinyl alcohol copolymer / adhesive layer / polyethylene.
• the first-mentioned multilayer films are particularly suitable.
• the biaxially oriented polyethylene terephthalate is coated with SiO x by plasma vacuum technology.
• the already produced polyethylene film is subsequently laminated thereon.
• Such a cover film is characterized in particular by excellent transparency and high breaking strength.
• packages having such a lidding film have an excellent gas barrier.
• the modulus of elasticity or the tensile stress according to ISO 527-2 is determined in the machine direction or in its transverse direction.
• a multilayer film according to the invention with the following layer structure: Layer A) a foam layer having a density of 0.47 g / cm 3 and a cell number of 492 cells / mm 3 of a mixture of 50 wt.% Polypropylene with a high-melt-strength polypropylene and 46 wt.% Of a heterophasic Propylene-ethylene block copolymers and 4% by weight of finely divided talc.
• Layer B from 100% by weight of a heterophasic propylene-ethylene block copolymer corresponding to the block copolymer of foam layer A)
• Layer C made of a polypropylene
• Layer D of a polypropylene-based adhesion promoter grafted with maleic anhydride units
• Layer E as a gas barrier layer based on an ethylene vinyl alcohol copolymer
• Layer F as a primer layer with the same structure as layer D
• Layer G as a sealing layer based on low density polyethylene.
• the multilayer film is produced by coextrusion.
• Table 1 The thickness of the individual layers is shown in Table 1.
• a multilayer film with identical layer sequence and up to layer A) having identical layer compositions and identical layer thicknesses was produced, wherein layer A) has the same polymer composition as in example 1 but no nucleating agents.

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• Laminated Bodies (AREA)
• Wrappers (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

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ID=34529829

Family Applications (1)

Country Status (12)

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• 2003
  • 2003-10-27 DE DE10350237A patent/DE10350237A1/de not_active Withdrawn
• 2004
  • 2004-10-25 WO PCT/EP2004/012029 patent/WO2005042245A1/de active Application Filing
  • 2004-10-25 BR BRPI0415876-8A patent/BRPI0415876A/pt not_active IP Right Cessation
  • 2004-10-25 US US10/577,090 patent/US20080020162A1/en not_active Abandoned
  • 2004-10-25 ES ES04790817.3T patent/ES2534461T3/es active Active
  • 2004-10-25 JP JP2006537154A patent/JP2007508972A/ja active Pending
  • 2004-10-25 HU HUE04790817A patent/HUE024467T2/en unknown
  • 2004-10-25 EP EP04790817.3A patent/EP1682343B1/de active Active
  • 2004-10-25 DK DK04790817.3T patent/DK1682343T3/en active
  • 2004-10-25 CA CA002543720A patent/CA2543720A1/en not_active Abandoned
  • 2004-10-25 RU RU2006118154/04A patent/RU2368507C2/ru active
  • 2004-10-25 PL PL04790817T patent/PL1682343T3/pl unknown

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